Stimulation of estrogen receptor accumulation by estradiol in primary cultures of salmon hepatocytes.

Hepatocytes of Salmo salar in primary culture form confluent monolayers and can be maintained at 11 degrees centigrade in serum-free medium for 8 days with minimal cell loss. Cultured hepatocytes from immature male salmon contain estrogen receptor both in nuclear and cytosol fractions (2000 and 2400 cites/cell, respectively). A single addition of estradiol results in an increase in the nuclear receptor to a level of 23 000 sites/cell after 24 h. This nuclear receptor concentration is similar to that in liver of estrogen-treated salmon in vivo, and is much higher than has been found for any other egg-laying vertebrate. The cultured salmon hepatocytes thus represent a highly sensitive system for the study of estrogen receptor dynamics and vitellogenesis in vitro.